KHR_composition_layer_color_scale_bias instead of raster alpha (#407)

wayvr/src/backend/openvr/mod.rs

@@ -314,7 +314,7 @@ pub fn openvr_run(show_by_default: bool, headless: bool) -> Result<(), BackendEr
                 let tgt = RenderTarget {
                     views: smallvec![o.ensure_staging_image(&mut app, meta.extent)?],
                 };
-                let mut rdr = RenderResources::new(app.gfx.clone(), tgt, &meta, 1.0)?;
+                let mut rdr = RenderResources::new(app.gfx.clone(), tgt, &meta)?;
                 o.render(&mut app, &mut rdr)?;
                 o.data.image_dirty = true;
                 futures.execute_results(rdr.end()?)?;

wayvr/src/backend/openxr/mod.rs

@@ -363,14 +363,14 @@ pub fn openxr_run(show_by_default: bool, headless: bool) -> Result<(), BackendEr
 
         for o in overlays.values_mut() {
             o.data.cur_visible = false;
-            let Some(alpha) = o.config.active_state.as_ref().map(|x| x.alpha) else {
+            if o.config
+                .active_state
+                .as_ref()
+                .is_none_or(|s| s.alpha < 0.01)
+            {
                 log::trace!("{}: hidden, skip render", o.config.name);
                 continue;
             };
-            if alpha < 0.01 {
-                log::trace!("{}: alpha too low, skip render", o.config.name);
-                continue;
-            }
 
             if !o.data.init {
                 log::trace!("{}: init", o.config.name);
@@ -378,11 +378,7 @@ pub fn openxr_run(show_by_default: bool, headless: bool) -> Result<(), BackendEr
                 o.data.init = true;
             }
 
-            let should_render = match o.should_render(&mut app)? {
+            let should_render = matches!(o.should_render(&mut app)?, ShouldRender::Should);
-                ShouldRender::Should => true,
-                ShouldRender::Can => (o.data.last_alpha - alpha).abs() > f32::EPSILON,
-                ShouldRender::Unable => false, //try show old image if exists
-            };
             log::trace!("{}: should_render returned: {should_render}", o.config.name);
 
             if should_render {
@@ -391,9 +387,8 @@ pub fn openxr_run(show_by_default: bool, headless: bool) -> Result<(), BackendEr
                 let stereo = !matches!(meta.stereo, StereoMode::None);
                 let wsi = o.ensure_swapchain_acquire(&app, &xr_state, meta.extent, stereo)?;
                 let tgt = RenderTarget { views: wsi.views };
-                let mut rdr = RenderResources::new(app.gfx.clone(), tgt, &meta, alpha)?;
+                let mut rdr = RenderResources::new(app.gfx.clone(), tgt, &meta)?;
                 o.render(&mut app, &mut rdr)?;
-                o.data.last_alpha = alpha;
                 futures.execute_results(rdr.end()?)?;
             } else if o.data.swapchain.is_none() {
                 log::trace!("{}: not showing due to missing swapchain", o.config.name);

wayvr/src/backend/openxr/overlay.rs

@@ -17,7 +17,6 @@ pub struct OpenXrOverlayData {
     pub(super) swapchain: Option<WlxSwapchain>,
     pub(super) init: bool,
     pub(super) cur_visible: bool,
-    pub(super) last_alpha: f32,
     color_bias_khr: Option<Box<xr::sys::CompositionLayerColorScaleBiasKHR>>,
 }
 

wayvr/src/overlays/screen/capture.rs

@@ -53,7 +53,6 @@ pub struct ScreenPipeline {
     mouse: BufPass,
     pass: SmallVec<[BufPass; 2]>,
     pipeline: Arc<WGfxPipeline<Vert2Uv>>,
-    buf_alpha: Subbuffer<[f32]>,
     extentf: [f32; 2],
     offsetf: [f32; 2],
     stereo: StereoMode,
@@ -76,29 +75,12 @@ impl ScreenPipeline {
                 .use_updatable_descriptors(smallvec![0]),
         )?;
 
-        let buf_alpha = app
-            .gfx
-            .empty_buffer(BufferUsage::TRANSFER_DST | BufferUsage::UNIFORM_BUFFER, 1)?;
-
         let mut me = Self {
-            pass: smallvec![Self::create_pass(
+            pass: smallvec![Self::create_pass(app, pipeline.clone(), extentf, offsetf,)?],
-                app,
+            mouse: Self::create_mouse_pass(app, pipeline.clone(), extentf, offsetf)?,
-                pipeline.clone(),
-                extentf,
-                offsetf,
-                buf_alpha.clone()
-            )?],
-            mouse: Self::create_mouse_pass(
-                app,
-                pipeline.clone(),
-                extentf,
-                offsetf,
-                buf_alpha.clone(),
-            )?,
             pipeline,
             extentf,
             offsetf,
-            buf_alpha,
             stereo,
         };
         me.ensure_stereo(stereo);
@@ -121,7 +103,6 @@ impl ScreenPipeline {
                 self.pipeline.clone(),
                 self.extentf,
                 self.offsetf,
-                self.buf_alpha.clone(),
             )?);
         }
 
@@ -146,13 +127,7 @@ impl ScreenPipeline {
         self.offsetf = offsetf;
         self.pass.clear();
 
-        self.mouse = Self::create_mouse_pass(
+        self.mouse = Self::create_mouse_pass(app, self.pipeline.clone(), extentf, offsetf)?;
-            app,
-            self.pipeline.clone(),
-            extentf,
-            offsetf,
-            self.buf_alpha.clone(),
-        )?;
         Ok(())
     }
 
@@ -161,14 +136,12 @@ impl ScreenPipeline {
         pipeline: Arc<WGfxPipeline<Vert2Uv>>,
         extentf: [f32; 2],
         offsetf: [f32; 2],
-        buf_alpha: Subbuffer<[f32]>,
     ) -> anyhow::Result<BufPass> {
         let set0 = pipeline.uniform_sampler(
             0,
             app.gfx_extras.fallback_image.clone(),
             app.gfx.texture_filter,
         )?;
-        let set1 = pipeline.buffer(1, buf_alpha)?;
         let buf_vert = app
             .gfx
             .empty_buffer(BufferUsage::TRANSFER_DST | BufferUsage::VERTEX_BUFFER, 4)?;
@@ -179,7 +152,7 @@ impl ScreenPipeline {
             buf_vert.clone(),
             0..4,
             0..1,
-            vec![set0, set1],
+            vec![set0],
             &Default::default(),
         )?;
 
@@ -191,7 +164,6 @@ impl ScreenPipeline {
         pipeline: Arc<WGfxPipeline<Vert2Uv>>,
         extentf: [f32; 2],
         offsetf: [f32; 2],
-        buf_alpha: Subbuffer<[f32]>,
     ) -> anyhow::Result<BufPass> {
         #[rustfmt::skip]
         let mouse_bytes = [
@@ -215,14 +187,13 @@ impl ScreenPipeline {
             .empty_buffer(BufferUsage::TRANSFER_DST | BufferUsage::VERTEX_BUFFER, 4)?;
 
         let set0 = pipeline.uniform_sampler(0, view, Filter::Nearest)?;
-        let set1 = pipeline.buffer(1, buf_alpha)?;
         let pass = pipeline.create_pass(
             extentf,
             offsetf,
             buf_vert.clone(),
             0..4,
             0..1,
-            vec![set0, set1],
+            vec![set0],
             &Default::default(),
         )?;
 
@@ -239,8 +210,6 @@ impl ScreenPipeline {
     ) -> anyhow::Result<()> {
         self.ensure_depth(app, rdr.cmd_bufs.len())?;
 
-        self.buf_alpha.write()?[0] = rdr.alpha;
-
         for (eye, cmd_buf) in rdr.cmd_bufs.iter_mut().enumerate() {
             let current = &mut self.pass[eye];
 
@@ -270,10 +239,6 @@ impl ScreenPipeline {
 
         Ok(())
     }
-
-    pub fn get_alpha_buf(&self) -> Subbuffer<[f32]> {
-        self.buf_alpha.clone()
-    }
 }
 
 fn stereo_mode_to_verts(stereo: StereoMode, array_index: usize) -> [Vert2Uv; 4] {

wayvr/src/overlays/wayvr.rs

@@ -451,17 +451,13 @@ impl OverlayBackend for WvrWindowBackend {
                 popup_img.clone(),
                 app.gfx.texture_filter,
             )?;
-            let set1 = self
-                .popups_pipeline
-                .buffer(1, self.pipeline.as_ref().unwrap().get_alpha_buf())?;
-
             let pass = self.popups_pipeline.create_pass(
                 extentf,
                 [BORDER_SIZE as _, (BAR_SIZE + BORDER_SIZE) as _],
                 buf_vert,
                 0..4,
                 0..1,
-                vec![set0, set1],
+                vec![set0],
                 &Default::default(),
             )?;
 

wayvr/src/shaders/screen.frag

@@ -5,13 +5,9 @@ layout (location = 0) in vec2 in_uv;
 layout (location = 0) out vec4 out_color;
 
 layout (set = 0, binding = 0) uniform sampler2D in_texture;
-layout (set = 1, binding = 0) uniform AlphaBlock {
-    uniform float alpha;
-};
 
 void main()
 {
     out_color = texture(in_texture, in_uv);
-    out_color.a = alpha;
 }
 

wayvr/src/windowing/backend.rs

@@ -47,18 +47,12 @@ pub struct RenderTarget {
 }
 
 pub struct RenderResources {
-    pub alpha: f32,
     pub cmd_bufs: SmallVec<[GfxCommandBuffer; 2]>,
     pub extent: [u32; 2],
 }
 
 impl RenderResources {
-    pub fn new(
+    pub fn new(gfx: Arc<WGfx>, target: RenderTarget, meta: &FrameMeta) -> anyhow::Result<Self> {
-        gfx: Arc<WGfx>,
-        target: RenderTarget,
-        meta: &FrameMeta,
-        alpha: f32,
-    ) -> anyhow::Result<Self> {
         let mut cmd_bufs = SmallVec::new_const();
 
         for tgt in target.views {
@@ -70,7 +64,6 @@ impl RenderResources {
 
         Ok(Self {
             cmd_bufs,
-            alpha,
             extent: meta.extent,
         })
     }